#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
#include<cstring>
#include<queue>
#include<cstdlib>
#include<vector>
#include<map>
#include<stack>
#include<set>
using namespace std;
const int maxn=1e5+100;
int pre[maxn];
int plane[maxn];
int sum[maxn];
int high[maxn];
int find(int x){
	if(x==pre[x])
		return pre[x];
	else
		return find(pre[x]);
}
void join(int x,int y){
	int fx,fy;
	fx=find(x);
	fy=find(y);
	if(fx!=fy){
		if(high[fx]>high[fy]){
			pre[fy]=fx;
			high[fx]=max(high[fx],high[fy]+1);
		}else{
			pre[fx]=fy;
			high[fy]=max(high[fy],high[fx]+1);
		}
	}
}
int main(){
	int n,m;
	while(~scanf("%d %d",&n,&m)){
		memset(sum,0,sizeof(sum));
		memset(pre,0,sizeof(pre));
		memset(high,1,sizeof(high));
		for(int i=1;i<=n;i++){
			pre[i]=i;
		}
		for(int i=1;i<=m;i++){
			int u,v;
			scanf("%d %d",&u,&v);
			join(pre[u],pre[v]);
		}
		for(int i=1;i<=n;i++){
			sum[find(pre[i])]++;
		}
		sort(sum+1,sum+1+n);
		printf("%d\n",sum[n]);
	}
	return 0;
}